Reserved Seat at the Hotel Restaurant?

There's something that's been bothering me for a while... A hotel was built near my place, and before it opened. I saw a woman sitting at the leftmost window seat in the first-floor restaurant. It was likely during staff training at the time. Even at 9 AM, it wasn't a break time, yet she was sitting there alone, head bowed. I happened to stop at a red light and she came into view. I couldn't help but stare, but the moment my car started moving and I looked away, she was gone. I didn't even see her leave, she just vanished... Ever since, even after the hotel opened, I see her every time I pass by. She doesn't look like she's in uniform, and it's been quite a while since the opening, but she's in almost the same seat almost every day for a customer. (I don't pass by every day, so I haven't confirmed this.) She's there even during times when the restaurant isn't in use. She just sits there with her head down, doing nothing. Is she alive, or is she dead... It bothers me, so I keep looking.